This is our passion project male charater making for one of our clients.Didn't spend too much time to finish,but the clients are satisfied with him.
Now,we are working on some other game characters,you can find here:http://game-silkroad.com/game_en/case.html
Any opinions or ideas are appreciated.

If you're really looking for criticism, and want me to just force a suggestion, possibly less "muscle tone" on the female, and that's a stretch. I just have a vague sense of muscle tone from her back and elbows. I think it may look the part a bit more if she were a bit "softer."

There are just two minor observations.
First, there's some kind of inconsistency in the normal maps (?). The first male character displays really outstanding foldings at arms and pants (little bit too much), whereas the details at the body looks quite flat (maybe it is just the lighting).

The second one is, that you should create a better show off of your character. Create a small plattform, pose your char, use some fancy camera perspective, choose the right background and atleast 3-point lighting to render your art more impressive. Eg. the dark train on a dark background is really hard to read. Just pimp your presentation to justify your great work.